Capacitors are one type of component commonly used in the fabrication of integrated circuits, for example in the fabrication of logic and memory circuitry. A typical capacitor includes two conductive electrodes separated by a non-conducting dielectric region. As integrated circuitry density has increased, there is a continuing challenge to maintain sufficiently high storage capacitance despite typical decreasing capacitor area. The increase in density of integrated circuitry has typically resulted in greater reduction in the horizontal dimension of capacitors as compared to the vertical dimension. In many instances, the vertical dimension of capacitors has increased.
A continuing goal in capacitor fabrication and integrated circuitry design is to achieve suitable high capacitance despite decreasing capacitor size. The degree of capacitance is impacted by a number of variables including capacitor size, capacitor shape/design, materials from which the capacitor is made, and thicknesses of the various capacitor layers. In many instances, there is a trade-off between parameters which tend to increase capacitance yet which can also undesirably impact undesired attributes of a capacitor. For example, certain parameters which tend to increase capacitance can undesirably also increase leakage of the capacitor electrodes through the capacitor dielectric between the electrodes and/or reduce the breakdown voltage at which the capacitor would fail.
While the invention was motivated in addressing the above identified issues, it is in no way so limited. The invention is only limited by the accompanying claims as literally worded, without interpretative or other limiting reference to the specification, and in accordance with the doctrine of equivalents.